Thank you for the advice! I've skipped test cases regarding resizing the disk. The remaining tests are "indirect" and "basic". vhost-user-blk device has now passed the "basic" test (/x86_64/pc/i440FX-pcihost/pci-bus-pc/pci-bus/vhost-user-blk-pci/vhost-user-blk/vhost-user-blk-tests/basic) as virtio-blk-deivce. But it fails the "indirect" test because libvhost-user doesn't support VIRTIO_RING_F_INDIRECT_DESC (indirect buffer descriptors), Would you suggest me to improve libvhost-user to support indirect buffer descriptors?
On Fri, Dec 13, 2019 at 6:58 PM Stefan Hajnoczi <stefa...@redhat.com> wrote: > On Wed, Dec 11, 2019 at 11:25:32PM +0800, Coiby Xu wrote: > > I'm now writing the tests for vhost-user-blk device based on > > tests/virtio-blk-test.c. But block_resize command doesn't apply to > > vhost-user-blk device. > > > > After launching vhost-user backend server, I type the following > > command to connect to it > > > > (qemu) chardev-add socket,id=char1,path=/tmp/vhost-user-blk_vhost.socket > > (qemu) object_add memory-backend-memfd,id=mem,size=256M,share=on > > (qemu) device_add vhost-user-blk-pci,id=blk0,chardev=char1 > > (qemu) block_resize blk0 512 > > Error: Cannot find device=blk0 nor node_name= > > > > QEMU can't find the device although in the guest OS I can already > > mount /dev/vda. And `info block` doesn't list the newly added > > vhost-user-blk device, > > (qemu) info block > > disk (#block154): dpdk.img (raw) > > Attached to: /machine/peripheral-anon/device[0] > > Cache mode: writeback > > > > floppy0: [not inserted] > > Attached to: /machine/unattached/device[17] > > Removable device: not locked, tray closed > > > > sd0: [not inserted] > > Removable device: not locked, tray close > > > > It seems `info block` and `block_resize` only work with `drive_add` > > which is not necessary for vhost-user-blk device. > > Yes, -device vhost-user-blk doesn't have a BlockDriverState (-drive or > -blockdev) because it communicates with the vhost-user device backend > over a character device instead. > > > Should I let QEMU > > support adding vhost-user backend device in the way similar to adding > > NBD device(`drive_add -n buddy > > > file.driver=nbd,file.host=localhost,file.port=49153,file.export=disk,node-name=nbd_client1`), > > i.e., a drive can be added via `drive_add -n buddy > > > file.driver=vhost-user,file.sock=/tmp/vhost-user-blk_vhost.socket,node-name=vhost_user_client1`? > > That is probably too much work. It's fine to skip test cases that > resize the disk. > > Stefan > -- *Best regards,* *Coiby*
